Got this call on 7/25/14 at 6:25 p.m.  Caller ID showed MED.  No one answered after receiver was picked up.

Robo call, I answered the call but said nothing, if it was a real person they would have said something first.
After 20 seconds it disconnected. A machine will wait for a voice to start their pitch or connect you to the telemarketer.
Try it, answer unknown calls with silence.

Did not recognize call on caller I'd just let it go on machine but caller , sub- human ,or THING,did not leave message.

My husband and I just let it ring its heart out.  Love the sound.

Called at 7:51 pm and left no message.  Caller ID indicated the caller as "MED."